hg: obtain lock when creating share from pooled repo (
issue5104)
There are race conditions between clients performing a shared clone
to pooled storage:
1) Clients race to create the new shared repo in the pool directory
2) 1 client is seeding the repo in the pool directory and another goes
to share it before it is fully cloned
We prevent these race conditions by obtaining a lock in the pool
directory that is derived from the name of the repo we will be
accessing.
To test this, a simple generic "lockdelay" extension has been added.
The extension inserts an optional, configurable delay before or after
lock acquisition. In the test, we delay 2 seconds after lock acquisition
in the first process and 1 second before lock acquisition in the 2nd
process. This means the first process has 1s to obtain the lock. There
is a race condition here. If we encounter it in the wild, we could
change the dummy extension to wait on the lock file to appear instead
of relying on timing. But that's more complicated. Let's see what
happens first.
Issue835: qpush fails immediately when patching a missing file, but
remaining added files are still created empty which will trick a
future qrefresh.
$ cat > writelines.py <<EOF
> import sys
> path = sys.argv[1]
> args = sys.argv[2:]
> assert (len(args) % 2) == 0
>
> f = file(path, 'wb')
> for i in xrange(len(args)/2):
> count, s = args[2*i:2*i+2]
> count = int(count)
> s = s.decode('string_escape')
> f.write(s*count)
> f.close()
> EOF
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init normal
$ cd normal
$ python ../writelines.py b 10 'a\n'
$ hg ci -Am addb
adding b
$ echo a > a
$ python ../writelines.py b 2 'b\n' 10 'a\n' 2 'c\n'
$ echo c > c
$ hg add a c
$ hg qnew -f changeb
$ hg qpop
popping changeb
patch queue now empty
$ hg rm b
$ hg ci -Am rmb
Push patch with missing target:
$ hg qpush
applying changeb
unable to find 'b' for patching
2 out of 2 hunks FAILED -- saving rejects to file b.rej
patch failed, unable to continue (try -v)
patch failed, rejects left in working directory
errors during apply, please fix and qrefresh changeb
[2]
Display added files:
$ cat a
a
$ cat c
c
Display rejections:
$ cat b.rej
--- b
+++ b
@@ -1,3 +1,5 @@
+b
+b
a
a
a
@@ -8,3 +10,5 @@
a
a
a
+c
+c
Test missing renamed file
$ hg qpop
popping changeb
patch queue now empty
$ hg up -qC 0
$ echo a > a
$ hg mv b bb
$ python ../writelines.py bb 2 'b\n' 10 'a\n' 2 'c\n'
$ echo c > c
$ hg add a c
$ hg qnew changebb
$ hg qpop
popping changebb
patch queue now empty
$ hg up -qC 1
$ hg qpush
applying changebb
patching file bb
Hunk #1 FAILED at 0
Hunk #2 FAILED at 7
2 out of 2 hunks FAILED -- saving rejects to file bb.rej
b not tracked!
patch failed, unable to continue (try -v)
patch failed, rejects left in working directory
errors during apply, please fix and qrefresh changebb
[2]
$ cat a
a
$ cat c
c
$ cat bb.rej
--- bb
+++ bb
@@ -1,3 +1,5 @@
+b
+b
a
a
a
@@ -8,3 +10,5 @@
a
a
a
+c
+c
$ cd ..
$ echo "[diff]" >> $HGRCPATH
$ echo "git=1" >> $HGRCPATH
$ hg init git
$ cd git
$ python ../writelines.py b 1 '\x00'
$ hg ci -Am addb
adding b
$ echo a > a
$ python ../writelines.py b 1 '\x01' 1 '\x00'
$ echo c > c
$ hg add a c
$ hg qnew -f changeb
$ hg qpop
popping changeb
patch queue now empty
$ hg rm b
$ hg ci -Am rmb
Push git patch with missing target:
$ hg qpush
applying changeb
unable to find 'b' for patching
1 out of 1 hunks FAILED -- saving rejects to file b.rej
patch failed, unable to continue (try -v)
patch failed, rejects left in working directory
errors during apply, please fix and qrefresh changeb
[2]
$ hg st
? b.rej
Display added files:
$ cat a
a
$ cat c
c
Display rejections:
$ cat b.rej
--- b
+++ b
GIT binary patch
literal 2
Jc${No0000400IC2
$ cd ..
Test push creating directory during git copy or rename:
$ hg init missingdir
$ cd missingdir
$ echo a > a
$ hg ci -Am adda
adding a
$ mkdir d
$ hg copy a d/a2
$ hg mv a d/a
$ hg qnew -g -f patch
$ hg qpop
popping patch
patch queue now empty
$ hg qpush
applying patch
now at: patch
$ cd ..